Radiometric dating technology
The carbon 14 present in an organism at the time of its death decays at a steady rate, and so the age of the remains can be calculated from the amount of carbon 14 that is left. The cells of all living things contain carbon atoms that they take in from their environment.
Back in the 1940s, the American chemist Willard Libby used this fact to determine the ages of organisms long dead.
The first is that atoms have always decayed at the same rate.
And this isn’t really an assumption as the decay rates have been tested in the laboratory for a hundred years or so, we have an example of a natural nuclear reactor where we can measure the various products and determine the decay rates (and the fine structure constant), and we can observe the past by looking deep into the past of the universe. The sigh isn’t for the effort of writing, it’s for the effort of finding all the references.
A form of radiometric dating used to determine the age of organic remains in ancient objects, such as archaeological specimens, on the basis of the half-life of carbon-14 and a comparison between the ratio of carbon-12 to carbon-14 in a sample of the remains to the known ratio in living organisms. A technique for measuring the age of organic remains based on the rate of decay of carbon 14.Archaeologists have long used carbon-14 dating (also known as radiocarbon dating) to estimate the age of certain objects.Traditional radiocarbon dating is applied to organic remains between 500 and 50,000 years old and exploits the fact that trace amounts of radioactive carbon are found in the natural environment.Indeed, by doing almost 20 seconds of research on google (type in “variations in C14”, click on Google Scholar) the second link is this article from 1954: Carbon 13 in plants and the relationships between carbon 13 and carbon 14 variations in nature So, this issue has been known about for a long time. Then we compare the two and adjust the radiocarbon date to the known date. That’s less than 1% if you’re interested in that sort of thing. But this is already almost a thousand words and I’ve only done ONE! Long story short, scientists have always known that variations in C-14 concentration happen.
Do you honestly think that no one has done anything about it? By making thousands (if not millions) of these adjustments we get a very good idea of how old a piece of unknown material can be. The 2009 calibration set extends the ‘well calibrated range’ to 50,000 years using the varves in a Japanese lake. This is unlike the creationists which think it happened, but can’t be bothered to check.
Over the past six decades, the amount of radiocarbon in people or their remains depends heavily on when they were born or, more precisely, when their tissues were formed.